References of "Steemans, Philippe"
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See detailOvulate structure early origin and diversification: did something happen during the Givetian?
Prestianni, Cyrille ULg; Ville de Goyet, F. de; Breuer, P. et al

Conference (2006)

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See detailComputer Assisted Spore Classification based on Ornament Spatial Distribution Analysis – An Application to Emsian Miospores from Saudi Arabia
Dislaire, Godefroid; Breuer, Pierre; Filatoff, John et al

Conference (2006)

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See detailMorphological variability of some Devonian miospores
Breuer, P.; Filatoff, J.; Steemans, Philippe ULg

in Palaeozoic palynology in space and time. CIMP general meting (2006)

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See detailEnigmatic Givetian palynomorphs
Steemans, Philippe ULg

Report (2006)

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See detailDisused Palaeozoic regional stages from Belgium: Devillian, Revinian, Salmian, Gedinnian and Burnotian.
Dejonghe, L.; Herbosch, A.; Steemans, Philippe ULg et al

in Geologica Belgica (2006), 9(1-2), 191-197

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See detailMorphometric analysis of proposed evolutionary lineages of Early Devonian land plant spores
Breuer, P.; Stricanne, L.; Steemans, Philippe ULg

in Geological Magazine (2005), 142(3), 241-253

Early Devonian miospore assemblages from 'La Gileppe' (Eastern Belgium) include five varieties of trilete spore belonging to the genus Emphanisporites. These five varieties show a continuous variation of ... [more ▼]

Early Devonian miospore assemblages from 'La Gileppe' (Eastern Belgium) include five varieties of trilete spore belonging to the genus Emphanisporites. These five varieties show a continuous variation of their morphological characteristics. The variation in morphological characteristics can be related to the evolution of morphological features and allows us to define the Emphanisporites micromatus Morphon. A statistical evaluation of this population highlights the interdependence of almost all morphological parameters. This study proves the increase in size of ornamental and structural parameters over several million years. The biometric changes and the progressive replacement of older morphotypes by younger ones indicate that a temporal link exists between these different varieties. Two phylogenetic hypotheses for the E. micromatus Morphon are proposed. This morphological evolution is so far observed only on the Eastern Old Red Sandstone Continent and defines a palaeophytogeographic sinuosus-zavallatus Province. [less ▲]

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See detailLochkovian (earliest Devonian) miospores from the Solimoes Basin, northwestern Brazil
Rubinstein, C.; Melo, J. H. G.; Steemans, Philippe ULg

in Review of Palaeobotany and Palynology (2005), 133(1-2), 91-113

Eighteen core samples from PETROBRAS well 1-JD-1-AM (Jandiatuba area. Solimoes Basin. northwestern Brazil) have been studied for miospores. Fifty-three species are identified. This assemblage is ... [more ▼]

Eighteen core samples from PETROBRAS well 1-JD-1-AM (Jandiatuba area. Solimoes Basin. northwestern Brazil) have been studied for miospores. Fifty-three species are identified. This assemblage is tentatively correlated with the Z Phylozone of the BZ Oppel Zone (Steemans, P., 1989. Palynostratigraphie de l'Eodevonien dans l'ouest de l'Europe. Professional Paper. Memoires Explicatifs pour les Caries Geologiques and Mineralogiques de la Belgique, 27, pp. 453.), dated late Lochkovian, This is in accordance with previous age determinations based on chitinozoans and acritarchs. Numerous representatives of the miospore genus Dictyotriletes are observed. These enable recognition of the Dictyotriletes emsiensis morphon. an informal classification unit which includes Dictyotriletes granulatus, D. emsiensis, Dictyotriletes cf. subgranifer, specimens previously misassigned to D. subgranifer and some Dictyotriletes spp. provisionally left in open nomenclature. Since all intermediate forms from typical D. granulatus to typical D. emsiensis coexist. it is currently difficult to determine the base of "F" Interval Biozone in South America as originally defined in Western Europe. It is suggested. therefore. that the base of the "Ems" Biozone defined in Brazil cannot be correlated with the base of die "E" Biozone. Instead. it be included in an interval of uncertainty ranging from the European "Si" to "E" Biozones. Indeed. the underlying "NsZ" Biozone from South America, contains species not known below the "Si" Biozone. Here, the D. emsiensis morphon Assemblage Zone is erected, which may, be coeval with the "N" through "E" Biozones of Western Europe. The PISA palynoflora from the Parana Basin is also attributed to this new biozone. However, in the absence of species observed in the "BZ" Biozone (and also in the Solimoes Basin). the PISA assemblage could be somewhat older than that of well 1-JD-1-AM. (C) 2004 Elsevier B.V. All rights reserved. [less ▲]

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See detailThe Middle-Devonian proto-ovule Runcaria heinzelinii Stockmans 1968
Gerrienne, Philippe ULg; Meyer-Berthaud, B.; Fairon-Demaret, Muriel ULg et al

Conference (2005)

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See detailPre-Cambrian to Palaeozoic Palaeopalynology and Palaeobotany
Steemans, Philippe ULg; Javaux, Emmanuelle ULg

in Carnets de Géologie = Notebooks on Geology (2005), Mémoir 2005/02

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See detailStratigraphic palynology of Devonian boreholes from northern Saudi Arabia
Breuer, P.; Al-Ghazi, A.; Filatoff, J. et al

in Carnets de Géologie = Notebooks on Geology (2005), Memoir 2005/02, CG2005 M02/01

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See detailPalyWeb
Steemans, Philippe ULg

Textual, factual or bibliographical database (2005)

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See detailRuncaria, a middle Devonian seed plant precursor
Gerrienne, Philippe ULg; Meyer-Berthaud, B.; Fairon-Demaret, Muriel ULg et al

in Science (2004), 306(5697), 856-858

The emergence of the seed habit in the Middle Pateozoic was a decisive evolutionary breakthrough. Today, seed plants are the most successful plant lineage, with more than 250,000 living species. We have ... [more ▼]

The emergence of the seed habit in the Middle Pateozoic was a decisive evolutionary breakthrough. Today, seed plants are the most successful plant lineage, with more than 250,000 living species. We have identified a middle Givetian (385 million years ago) seed precursor from Belgium predating the earliest seeds by about 20 million years. Runcaria is a small, radially symmetrical, integumented megasporangium surrounded by a cupule. The megasporangium bears an unopened distal extension protruding above the multilobed integument. This extension is assumed to be involved in anemophilous pollination. Runcaria sheds new light on the sequence of character acquisition leading to the seed. [less ▲]

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See detailThe Moesian Terrane during the Lochkovian - a new palaeogeographic and phytogeographic hypothesis based on miospore assemblages
Steemans, Philippe ULg; Lakova, I.

in Palaeogeography, Palaeoclimatology, Palaeoecology (2004), 208(3-4), 225-233

The relative position of terranes during the Palaeozoic can be indicated by a combination of palaeomagnetic and floral/faunal evaluation. Palaeomagnetic data are absent from the Moesian Terrane, South ... [more ▼]

The relative position of terranes during the Palaeozoic can be indicated by a combination of palaeomagnetic and floral/faunal evaluation. Palaeomagnetic data are absent from the Moesian Terrane, South-Eastern Europe, and its position is here estimated thanks to palaeophytogeographic considerations based on miospore assemblages. Miospore assemblages have been studied in two boreholes from northern Bulgaria. Preliminary analyses of chitinozoans, acritarchs and phytodebris have already been published. The oldest samples were considered to be of Pridoli age based on chitinozoan data, but here we provide new miospore evidence suggesting a Lochkovian age. This age determination is in accordance with the new interpretations based on previously published acritarch data. It is likely that the previous Pridoli age determination was influenced by Pridoli chitinozoans being reworked into the Lochkovian. The miospores are typical of assemblages only present in a small area of Avalonia and the western part of the Baltica Plate, and belong to the sinuosus-zavallatus (S-Z) Phytogeographic Province, defined here. On the contrary to the miospores, marine palynomorphs have affinity with Gondwanan assemblages. The different palaeogeographic affinities of the different palynomorph groups are not necessarily in contradiction, as it has recently been suggested that the Rheic Ocean did not act, around the Silurian-Devonian boundary, as a hermetic barrier for transoceanic chitinozoan and acritarch exchange. Therefore, the results are tentatively interpreted as indicating that the Moesian Terrane, belonging to the S-Z Province, was close to southern Laurussia during the Lower Devonian. This northern position of the Moesian Terrane during the Lower Devonian conflicts with most current palaeogeographic reconstructions, but partially supports the hypothesis of a migration of this terrane from Gondwana to Laurussia during the Palaeozoic. The possible presence of reworked palynomorphs in the Lochkovian may reflect early tectonic events associated with the close proximity of the Moesian Terrane and the Dobrudgea periphery of Palaeo-Europe. (C) 2004 Elsevier B.V. All rights reserved. [less ▲]

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See detailMiospores and the emergence of land plants
Steemans, Philippe ULg; Wellman, C. H.

in Webby, B.; Paris, F.; Droser, M.L. (Eds.) et al The Great Ordovician Biodiversification Event (2004)

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See detailPosition of the Moesian platform at the Lochkovian. Hypothesis based on miospores
Steemans, Philippe ULg; Lakova, I.; Breuer, P.

Conference (2004)

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See detailLlandovery biostratigraphy of the Paraná Basin, East Paraguay
Mendlowicz Mauller, P.; Pereira, E.; Grahn, Y. et al

Conference (2004)

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See detailPalynology of the Jauf Formation from the Northeastern part of the Arabian Shield
Al-Ruwaili, M.; Breuer, P.; Higgs, K. et al

Conference (2004)

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